This Facility will provide comprehensive support for microarray-based studies related to NHLBI funded research programs at the University of California San Francisco (UCSF). UCSF is a major site for NHLBI-funded research. Strong institutional support from UCSF and the affiliated Gladstone Institutes enabled us to establish a microarray facility and gain experience with GeneChip and spotted arrays. Recent technology development efforts in the Facility have focused on production and validation of human and mouse spotted oligonucleotide arrays and collaborative development of a web-based open source microarray database system. This grant, coupled with ongoing institutional support, will enable us to expand the Facility to allow integration of GeneChip and spotted oligonucleotide array technology into many NHLBI-supported projects. This application includes eleven proposals for microarray studies involving projects directed by 14 UCSF investigators and funded by a total of 17 different NHLBI grants. We also describe plans for supporting new NHLBI-funded projects. Each project will collaborate closely with the Facility to surmount the challenges posed by microarray technology and to use the technology to generate and test important and novel hypotheses. The Facility will provide technical training and consultation and cost-effective access to arrays and related equipment. Experts in bioinformatics and biostatistics will promote the use of state of the art approaches to data analysis and dissemination. The Facility will also take an active role in implementing new methods that will be useful for all participating projects. Designation of our Facility as a Shared Microarray Facility will have a major impact on a large and productive group of NHLBI-supported researchers at UCSF.